1. Field of the Invention
The present invention pertains to the art of electrical circuit testers and, more particularly, to an electrical circuit test module which interfaces with a standard electrical circuit tester to test arc fault circuit interrupter (AFCI) protected circuits.
2. Discussion of the Prior Art
Electrical receptacles are found throughout households and commercial locations. Actually, every room in a household or commercial location is provided with multiple receptacles so as to minimize the need for extension cords and adapters that enable multiple loads to be run through a single receptacle. During installation, the receptacles must be tested to ensure proper wiring and grounding. More specifically, in order to meet local and national code requirements, each receptacle must have the proper polarity and must be properly grounded. To test for proper wiring, an electrician will employ a testing device to ascertain if the receptacle is wired correctly. The testing device can range anywhere from a simple receptacle tester, such as Model # 61-500 made by the IDEAL® Company, to more expensive multi-testers, both digital and analog, used in electronic testing.
In addition to standard, three-prong receptacles, the National Electric Code requires that certain locations, such as in outdoor applications, kitchens, bathrooms and the like, be protected by a ground fault circuit interrupter (GFCI) circuit breaker or receptacle. While all circuits are protected against over current conditions by fuses or circuit breakers, standard fuses and circuit breakers will not protect against a ground leak. The GFCI breaker/receptacle will cut off power to a load in the event a predetermined current level passes between a neutral conductor and ground. The GFCI protects the consumer from electrocution in the event of a ground leak, as a leak of this type will generally not trigger a standard circuit breaker.
Unlike standard receptacles, a GFCI breaker/receptacle includes a test button used to check the functionality of the GFCI. However, the test button is only an indication of functionality, i.e., no actual load is placed on the circuit. Therefore, to properly test a GFCI breaker/receptacle, a special testing device is required. Like the testing device for standard receptacles, the special GFCI testing device can range from a durable inexpensive model, such as IDEAL® E-Z Check® model # 61-051 to a more expensive, branch circuit tester, such as IDEAL® model # 61-154. Regardless of the particular model employed, each of these devices function by simulating an actual current leak to test the GFCI protected receptacle.
As described above, a traditional circuit breaker protects against an over current condition that exceeds a particular rating for the circuit breaker. One form of over current condition occurs as a result of hazardous arcing. When arcing occurs at current levels above which the circuit breaker is rated, the circuit breaker cuts off electricity to an affected receptacle or branch circuit. However, a traditional circuit breaker will not shut down power to a receptacle where arcing occurs at current levels below which the circuit breaker is rated.
Electrical arcing, whether at low or high levels, results in the production of heat. Arc faults can generally go undetected for an extended time, while generating temperatures as high as approximately 5000° F. (2760° C.) at low current levels. If left unchecked, the heat could cause a fire. In order to ensure that electricity is shut down to a receptacle experiencing low level arcing, an arc fault circuit interrupter (AFCI) must be employed. The National Electric Code now requires that all receptacles located in bedrooms be protected by an AFCI circuit breaker or receptacle. In a manner similar to that described above with respect to GFCI receptacles, an AFCI receptacle includes a test button that trips the AFCI function. However, also like the GFCI breaker/receptacle, the test is just an indication of functionality. No load is applied to the circuit. Therefore, a special test device is required to properly test the functionality of the AFCI device.
At present, testing devices capable of checking the performance of an AFCI protected circuit are either combined into other, more expensive, testing devices or are embodied in a tester much like the GFCI circuit/receptacle tester described above. At this point, many professionals have already invested in equipment for testing receptacles, GFCI protected circuits and the like. Without a tester capable of interfacing and expanding the capability of existing equipment, most professionals will be forced to invest in additional, more expensive equipment or carry additional, sometimes duplicative testers. Based on the above, there still exists a need for a need for a durable, low cost AFCI testing device capable of interfacing with existing circuit testing equipment, thereby enabling an electrician to adapt equipment designed for only testing GFCI protected circuits to also test AFCI protected circuits.